FR2903699A1 - Pulverulent mixture useful in liquid paint composition, comprises pigments mixed with a dispersing agent in a binder and resin with film forming properties, in a form to be diluted in water to obtain a film forming coloring composition - Google Patents

Abstract

Pulverulent mixture for liquid paint composition, comprises pigments in mixture with a dispersing agent in a binder and a resin with film forming properties, in a form to be diluted in water to obtain a film forming coloring composition. An independent claim is included for a preparation of a liquid paint composition, by diluting the mixture in water.

Description

The present invention is in the field of paints, and more

  particularly paintable liquid paint compositions. The term "paint" is intended to mean both the actual paints, the varnishes, the stains and other compositions in liquid form intended to be applied in a thin layer on a surface to be covered. The term liquid also extends to the cream forms obtained by adding a thickener in the liquid composition.

  The paint compositions intended to be applied by brush typically contain one or more pigments chosen for their coloring power, one or more resins with film-forming properties, and various fillers and other additives. They are usually presented and marketed in liquid form.

  Such a form of presentation has the disadvantages of a large volume and weight pots containing the paint, which causes high costs for transport operations and storage of these pots. The invention aims to overcome the drawbacks of existing liquid paint compositions, and especially those set forth above, by proposing an economical solution to the problem of transport and storage of paint compositions applicable to the brush. For this purpose, the invention proposes a powder mixture for liquid paint composition, which comprises pigments mixed with a dispersing agent in a binder and a resin with film-forming properties, and which is presented in a form to be diluted in a quantity of water determined so as to obtain a film-forming coloring composition.

  Throughout the present description, by powder means a mixture in the form of non-dusty powders, having an average particle size greater than 10 microns, and in all cases greater than that of the separated constituents. The mixture is preferably advantageously in the form of aggregates not containing dust, with an average particle size of between 200 and 1000 microns. Thus, according to the invention, the only pots to be transported and stored at the point of sale are those containing the powder mixture. The end user buys these pots and he himself performs the final operation, which is the dilution in an appropriate amount of water, directly to the place where the painting work is to be done. The costs associated with transport and storage are thus advantageously reduced, since the volume of the powder alone, as well as its weight, are much smaller than those of the paints in liquid form, for the same painted surface capacity. The dilution is carried out in water or in any other aqueous vehicle suitable for such an application. In addition, the mixture according to the invention is particularly advantageous from the economic point of view, since the end user thus has the possibility of diluting in water only the quantity of powder which he punctually needs, the rest of powder being able to be kept in the pot until the next use. As a result, the wasteful problems of liquid paints that dry in the bottom of pots are eliminated. In addition, when used later, it is ensured to obtain the same coloration, respecting the same proportions of powder and aqueous vehicle.

The binder, the resin and the dispersing agent are selected to be soluble in the aqueous vehicle. The pigments that can be used in the context of the invention are advantageously of all types: organic, such as phthalocyanine blue, phthalocyanine green, diketo-pyrrolopyrrole red, naphthol red, azo yellows, pigments derivatives of isoindoline, benzimidazolone, etc., or minerals, such as titanium dioxide, iron oxides (opaque or transparent), chromium oxide, cobalt blue, bismuth vanadate, etc. These pigments can be used alone or as a mixture, which is quite advantageous from the point of view of the color palette that can be obtained within the scope of the invention. They are initially, in a conventional manner, in the form of a powder of ultrafine particle size, of the order of a few tens of 5 microns. The pigments have the characteristic of being insoluble in water, so that it is necessary to disperse them in this vehicle in order to obtain a liquid paint composition. According to the invention, the preparation of such a composition is advantageously simple, since it suffices for the user to simply pour into the appropriate volume of water the desired quantity of powder mixture, and in the preferred embodiments of the invention in the form of aggregates. The constituents of the mixture which are soluble in water dissolve therein. A homogeneous dispersion of the pigments in the solution is ensured by the dispersing agent, so that a ready-to-use homogeneous paint composition is obtained directly and having all the characteristics necessary for the application, ie ie coloring power and film-forming capacity. In addition, the paint composition can be prepared extemporaneously, so that it is not necessary to include fungicidal agents to preserve it, unlike conventional liquid paints. The mixture according to the invention has the advantage of good conservation over time. According to an advantageous characteristic of the invention, the pigments and the dispersing agent are presented in the form of grains of powder containing them as a mixture in the binder, in which they have been incorporated according to the technique of granulation in the molten state, that is, in which they were previously incorporated dry (i.e., in powder form, in the absence of water or other solvents), and dissolved at a temperature greater than the melting temperature of the binder, so that solid granules containing the pigment particles and the dispersing agent in homogeneous mixture in the binder are obtained after cooling, each of the particles being individually coated in the mass of binder.

Such a method of preparation makes it possible, quite unexpectedly, to obtain a dispersion of the pigments in the aqueous vehicle, once the mass of binder coating the particles dissolved, which is not only homogeneous, but also stable in the 5 times. This is because of the presentation of pigments in the form of granules obtained in the molten state. Such a preparation process makes it possible to obtain granules of all shapes and all particle sizes. In practice, it is preferred to use granules of spherical or nodular shape, for example, which are easy to handle and have a dissolution rate in high water, and have a particle size of between 200 and 1000 microns, so that micron dust is not produced during handling of the granules.

The film-forming resin is also present in powder form as a single component or as a mixture of several components. Advantageously, a wide variety of resin types can be used in the context of the invention. Mention may be made, for example, of vinyl-type resins (vinyl esters such as vinyl acetate resins or vinyl versatate resins), resins derived from polyethylene (polyethylene resins, chlorinated or chlorosulfonated polyethylene), resins derived from styrene (polystyrene, styrene-butadiene and dispersions, acrylic styrene-butadiene resins), resins derived from rubber (isomerized or cyclized, chlorinated), chlorinated vinyl resins (polyvinyl chloride and other copolymers, vinylidene chloride, vinyl resins) polyfluoro, polyvinyl acetate, polyvinyl propionate), polyvinyl alcohols and their derivatives, polyvinyl acetals, butyrals, acrylic resins and acrylic dispersions (thermoplastic acrylates and methacrylates), resins derived from coal or petroleum ( coumarone-indene, hydrocarbon resins), mineral and hydraulic binders s such as cement, lime blossom, casein, etc.

The paint compositions obtained with the powder mixture according to the invention are advantageously usable on all types of materials, whether wood, metal, building materials .... They make it possible to obtain several levels. 5 gloss (matt, satin or glossy). According to preferred embodiments in industrial practice, the invention furthermore meets the following characteristics, implemented separately or in each of their technically operating combinations.

In preferred embodiments of the invention, the pigments are present in the mixture in a concentration of between 0.5 and 25% by weight, preferably about 8% by weight, of the total weight of the mixture. depending on the desired hiding power, hue, ultraviolet resistance, and paint quality. The resin is preferably present in a concentration of between 5 and 80% by weight, preferably about 45% by weight, of the total weight of the mixture, depending on the gloss, the quality of the paint and the performance of the paint. the desired resin. Such proportions, in conjunction with the amount of water to be combined with a particular amount of the mixture, advantageously make it possible to obtain a liquid composition having adequate coloring and film-forming properties for use as a paint. According to an advantageous characteristic of the invention, the dispersing agent is an effervescent agent, which produces its effect in contact with water, when the granules containing it in mixture with the pigments in the binder dissolve, creating in the solution Stirring which facilitates the dispersion of the pigment particles. The effectiveness of this dispersion is all the more important that the effervescent agent is present in the granules intimately mixed with the binder.

The use of an effervescent agent to ensure the dispersion of the pigment particles in the solution is particularly advantageous from the point of view of the quality of the coloring of the paint composition. Indeed, on the one hand, the effervescent agent ensures sufficient dispersion to avoid the need to resort in addition to mechanical dispersing means, which would have the effect of damaging the pigments. On the other hand, the effervescence created in the solution breaks the agglomerates of pigment particles, and separates them from each other, which has the effect of revealing the hue of the pigments. The resulting paint composition thus has high quality coloring. Such a preparation technology makes it possible to accelerate the dispersion of the constituents in the aqueous vehicle, to stabilize it over time, to regulate its pH. It also facilitates the process of dry granulation, so that the aggregates obtained are of better quality. Indeed, as part of its use in combination with the melt granulation process, the effervescent agent offers an additional advantage, which is to promote granulation. The granules obtained when the effervescent agent is present in the mixture are thus of better quality, in the sense that they contain a lower dust content. This advantageous result could be explained by the fact that, due to the presence of traces of water in the mixture during the implementation of the process, there occurs in this mixture a slight effervescence which has the effect of promoting the granulation. The effervescent agent is in practice a mixture of two compounds which are finely distributed individually in the binder so as to react with each other only in the presence of water. It is in particular a mixture of sodium carbonate and citric acid, in substantially stoichiometric proportions. This particular combination proves to be advantageous from the point of view of the stability of the liquid composition obtained, since the reaction between sodium carbonate and citric acid produces sodium citrate, which has the property of stabilizing the products in question. solution. The effervescent agent is preferably present in the mixture in a concentration of between 2 and 20% by weight, preferably about 15% by weight, based on the total weight of the mixture. This concentration advantageously makes it possible to ensure homogeneous, rapid and complete dispersion of the pigments in the aqueous vehicle as soon as the binder encapsulating them dissolves.

The dispersing agent may also, in the context of the invention, be a surfactant, or any other substance promoting the dispersion of micron-sized solid particles in a solution. In preferred embodiments of the invention, the binder has surfactant properties, so that it participates in the dispersion effect of the pigment particles in the aqueous vehicle, preventing the reagglomeration of the deagglomerated particles by the dispersing agent. Advantageously, in connection with the presence of the dispersing agent, a dispersion of the pigments in the water is obtained which is rapid, homogeneous and which remains stable over time. The binder consists in particular of a mixture of ethoxylated fatty alcohol and polyethylene glycol (PEG). The ethoxylated fatty alcohol is preferably an alkyl ether of polyethylene glycol fatty alcohol, which is preferably present in a proportion of about 50% by weight based on the total weight of said binder. In preferred embodiments of the invention, the binder is present in a proportion of between 5 and 60% by weight, preferably about 15% by weight, of the total weight of the mixture. This amount is sufficient to allow complete coating of all the constituents of the mixture.

In preferred embodiments of the invention, the pigments and the resin are present in the same grains of powder as a mixture in the binder in which they have previously been dissolved at a temperature above the melting point of 5 ° C. binder. The mixture according to the invention is thus advantageously in the form of a single powder, in which all the constituents, pigments, dispersing agent and resin, are coated in the same grains formed by the binder. This results in great ease of use, since the mixture is then homogeneous, and it avoids any risk of settling in the pot of some powders relative to others. This embodiment is the most advantageous from the point of view of the reproducibility of the coloration obtained from the same pot. The blend may also contain powder fillers and additives conventionally used for paint compositions. In other embodiments of the invention, the pigments and the resin are present in different powder grains. In this case, which is the simplest from the point of view of industrial manufacture, the pigments in self-dispersible form, for example prepared according to the principle of granulation in the molten state, and the resin are simply mixed, under form of separate powders. According to an advantageous characteristic of the invention, the pigments comprise, alone or in combination with color pigments, particles of titanium, a white pigment, which make it possible to obtain the desired shade of color in a proportion of from 0 to 25. % by weight relative to the total weight of the mixture. In preferred embodiments of the invention, the mixture further comprises additives which are conventional in themselves. These may include hardeners, thickeners (such as cellulose ether), catalysts (such as lime blossom), abrasion-resistant agents, and / or anti-foam agents (such as polysiloxane). ), in a total proportion of between 1 and 32% by weight, preferably about 17% by weight, of the total weight of the mixture. In particular, the antifoam agents have a very advantageous effect when they are used in the embodiments of the invention in which the dispersing agent is an effervescent agent, which is capable of inducing foaming in the solution. The mixture may also comprise surface-active agents, anti-corrosion pigments, fungicidal agents, anti-bacterial agents, anti-mite agents, water-repellent agents, and other conventional additives (rheological agents, hollow glass beads). surfactants, etc.).

The mixture according to the invention may also contain conventional fillers per se, such as calcium carbonate, talc, barium sulfate, mica, and the like. The composition according to the invention, in powder form, does not contain any solvent. It does not advantageously contain no more fungicidal agent necessary for the preservation of liquid paints in pots. It therefore meets the new European directives on VOCs (Volatile Organic Compounds), defined as solvents with a boiling point of less than 250 ° C at atmospheric pressure, and on fungicides, since it contains none of these substances. compounds. In preferred embodiments of the invention, the mixture is presented in a form which makes it possible to obtain a paint-forming coloring paint composition that can be applied by brush by diluting 1 to 2 parts of the mixture in 1 to 2 parts of water. In particular 50 g of the mixture in 50 ml of water. It is in particular presented in a can, or other container, containing a certain amount of powder and including a sufficient free volume so that it can be added, extemporaneously, the appropriate volume of water to allow obtaining a liquid paint composition having the desired properties. This adequate volume may in particular be indicated by a line of gauge disposed on a transparent wall of the can. The mixture according to the invention thus offers the following advantages: it does not contain VOCs; it does not require a fungicide necessary for the protection of the pot paint; it does not contain dust; there is no risk of drying the liquid paint during storage; there is no sedimentation as for liquid paint during storage; it does not fear frost during storage; it represents less weight to transport; it takes up less space on storage shelves; it is easy to handle. The invention also relates to a method for preparing a liquid paint composition, according to which a quantity of the mixture according to the invention is diluted in a specific quantity of water. After a few minutes the dissolution / dispersion of the various constituents was carried out, and a ready-to-use paint composition is obtained. The invention will now be further specified in its preferred features and advantageous results by the detailed description of particular embodiments which are the subject of the examples below. Unless otherwise stated, all figures or other indications shall be expressed in accordance with international standardization on the one hand, and in mass quantities on the other. Examples 1 to 8 Granules for paint compositions are produced by a melt granulation process in the following manner. The compounds given in Table 1 are dry blended, the proportions being expressed in% by weight relative to the total weight of the mixture. The pigments are defined in a conventional manner, according to their Color Index code.

2903699 11 Compound Ex.

1 Ex.

2 Ex.

3 Ex.

4 Ex.

Ex.

6 Ex.

7 Ex.

8 Blue 3% - - - - - -phthalocyanine Pigment - 3% - - - .. - - Red 254 Vanadate - - 3% - - - Bismuth Iron Oxide - - - 3% - - - - Yellow Oxide of - - - - 3% - - green chrome Pigment yellow - - - - - 3% - - 74 Purple pigment - .. - - - 3% - 23 5% 5% 5% 5% 5% 5 Dioxide 5 % 5% 5% titanium (white) 15% 15% 15% 15% 15% 15% 15% 15% PEG of fatty alcohol Resin 27,25% 27,25% 27,25% 27,25% 27.25% 27.25% 27.25% 27.25% Copolymer copolymer Copolymer 18.15% 18.15% 18.15% 18.15% 18.15% 18.15% 18.15% 18 , 15% vinyl acetate and vinyl versatate 15% 15% 15% 15% 15% 15% 15% 15% Calcium Ether 0.4% 0.4% 0.4% 0.4% 0.4% 0, 4% 0.4% 0.4% cellulose Fleur de lime 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0, 9% Defoamer: 0.25% 0.25% 0.25% 0.25% 0.25% 0.25% 0.25% 0.25% Polysiloxane Carbonate 8% 8% 8% 8% 8 % 8% 8% 8% soda Citric acid 7% 7% 7% 7% 7% 7% 7% 7% Table 1: composition of the granules of the Examples 1 to 8 The dry mixture is heated in a water bath at a temperature of about 100 ° C above the melting temperature of the binder until the binder is completely liquid. It is then cooled so as to ensure its precipitation in the form of solid granules, of average particle size less than 1 mm, which are collected and maintained with moderate stirring until complete cooling, in order to prevent their agglomeration into blocks. Examples 9 to 12 The procedure is as for Examples 1 to 8, to prepare granules from the constituents given in Table 2 below. Ex compound.

9 Ex.

Ex.

11 Ex.

12 Blue 45% - - 22% phthalocyanine Red pigment 254 _ 46% - 20% Yellow iron oxide _ _ 49% - Titanium dioxide 5% 4% 1 A, 8% (white) 35% 35% alkyl ether 35% 35% PEG of fatty alcohol Carbonate 8% 8% 8% 8% soda Citric acid 7% 7% 7% 7% Table 2: composition of the granules of Examples 9 to 12 The granules obtained are mixed dry to homogeneously, by mechanical means, with the following compounds presented in the form of powders: Granules of Examples 9 to 12 Copolymer resin of acrylate Copolymer of vinyl acetate 50 0/0 30.30 0/0 2903699 13 and versatate of vinyl 18.15% Cellulose Ether 0.3 lime Flower 1% Antifoam (Polysiloxane) 0.25% Powdered mixtures are obtained for liquid paint compositions ready to be diluted in water. Example 13 A quantity of 50 g of the granules of each of Examples 1 to 50 is respectively poured into a volume of 50 ml of water. In all cases, it is observed that the granules dissolve immediately. In the solutions there is a slight effervescence, with a slight formation of foam. At the same time, the solutions are stained homogeneously. After about 10 minutes, the foam is gone. The solutions are clear in appearance and have a homogeneous color. The pigment particles are finely dispersed. In all eight solutions, the dispersion of the pigments remains stable over time. It is maintained without the need to shake for several hours (up to 12 hours). The liquid compositions obtained have a coloring power and a film-forming capacity that are suitable for use as paints. EXAMPLE 14 The procedure is as in Example 13, with the powder compositions of Examples 9 to 12.

For the four solutions, a homogeneous dispersion of the pigments and the various other constituents is obtained. This dispersion remains stable over time. It is maintained without the need to shake for several hours.

The resulting liquid compositions have adequate coloring and film-forming ability to be used as paints. The foregoing description clearly explains how the invention proceeds in a manner that can not be predicted by those skilled in the art and how it achieves the goals it has set for itself. In particular, it provides a particularly economical powder mixture, which makes it easy to obtain, by simple dilution in an aqueous vehicle, a ready-to-use liquid paint composition. Nevertheless, it emerges from the foregoing that the invention is not limited to the embodiments which have been specifically described in the course of the examples above and which, on the contrary, extends to any variant passing through the through means 20 equivalents. In particular, the invention can also be applied in the same way for paint compositions whose solvent is not water but any other known organic solvent conventionally used in the field of paints, for example White Spirit.

Claims (14)

  1. A powder mixture for a liquid paint composition, comprising pigments mixed with a dispersing agent in a binder and a resin having film-forming properties, presented in a form to be diluted in a quantity of water determined so as to obtain a film-forming coloring composition .   2. Mixture according to claim 1, characterized in that said pigments and said dispersing agent are presented in the form of powder grains containing them as a mixture in said binder in which they have previously been dissolved at a temperature above the melting temperature of said binder.   3. Mixture according to claim 1 or 2, characterized in that said pigments are present in a concentration of between 0.5 and 25% by weight, preferably approximately equal to 8% by weight, of the total weight of the mixture.   4. Mixture according to any one of claims 1 to 3, characterized in that said resin is present in the form of a single constituent or a mixture, and in a concentration of between 5 and 80% by weight, preferably approximately equal to 45% by weight, of the total weight of the mixture.   5. Mixture according to any one of claims 1 to 4, characterized in that said dispersing agent is an effervescent agent, especially a mixture of sodium carbonate and citric acid. 2903699 16   6. Mixture according to claim 5, characterized in that said effervescent agent is present in a concentration of between 2 and 20% by weight, preferably approximately equal to 15% by weight, of the total weight of the mixture. 5   7. Mixture according to any one of claims 1 to 6, characterized in that said binder has surfactant properties, and in that it consists in particular of a mixture of polyethylene glycol and ethoxylated fatty alcohol.   Mixture according to Claim 7, characterized in that the ethoxylated fatty alcohol is an alkyl ether of polyethylene glycol of fatty alcohol, preferably present in a proportion of approximately 50% by weight relative to the total weight of said binder.   9. Mixture according to any one of claims 1 to 8, characterized in that said binder is present in a proportion of between 5 and 60% by weight, preferably approximately equal to 15% by weight, of the total weight of the mixture .   10. Mixture according to any one of claims 1 to 9, characterized in that said pigments and said resin are present in the same grains of powder, mixed in said binder in which they have previously been dissolved at a temperature greater than the melting temperature of said binder.   11. Mixture according to any one of claims 1 to 9, characterized in that said pigments and said resin are present in different powder grains. 25   12. Mixture according to any one of claims 1 to 11, characterized in that it further comprises additives, including hardeners, thickeners, catalysts, and / or antifoam agents, in a total proportion between 1 and 32% by weight, preferably about 17% by weight, of the total weight of the mixture.   13. Mixture according to any one of claims 1 to 12, characterized in that it is presented in a form for obtaining a paint-forming coloring paint composition that can be applied by brush by dilution of 1 to 2 parts of said mixture. in 1 to 2 parts of water, preferably 50 g of said mixture in 50 ml of water. 10   14. Process for the preparation of a liquid paint composition, characterized in that a quantity of the mixture according to any one of Claims 1 to 13 is diluted in a specific quantity of water.